In the art of aluminum die casting, it is necessary that the proper amount of molten metal be delivered to the die casting machine for each casting to be made. If too little metal is delivered, then the casting will have voids and will be defective. If too much metal is delivered, metal can be wasted, splashed around or excessive pressures can be developed in the die cavity resulting in the cavity opening and undesirable burrs or flash developing around the edges of the casting.
Heretofore it has been known to hand ladle the molten aluminum into the die casting apparatus. In such instance, the die castor had a ladle of a specified volume which he dipped into a heated vat of molten aluminum to a depth such that the aluminum scum or dross which forms on the surface of the aluminum will not be present on the top of the metal in the ladle. The ladle is then carried from the vat to the point of use and poured into the die casting machine input chamber.
Such an operation required labor to be present continuously and the handling of the molten metal by hand constituted a hazard for the laborer in the event the metal should be spilled and it was always difficult to accurately deliver exactly the same amount of molten metal to the die casting machine for every casting to be made. Also the pounds of metal which can be handled in a manually held ladle are limited.
It has been proposed to provide mechanical apparatus to perform such a function. Such apparatus heretofore commonly comprising a ladle which is mechanically dipped into the vat of molten metal below the surface so as to avoid the scum or dross on the top thereof and then raised out of the vat and moved across the room to the die casting apparatus. Such apparatus was expensive, cumbersome, complicated and difficult to maintain. Additionally there was always the danger of molten metal being spilled as the open ladle was moving from the vat to the die casting machine. Here again the maximum pounds of metal which can be handled is limited by the mechanical strength of the apparatus.